Segment-trimming instrument



F DOX. SEGMENT TRIMMING INSTRUMENT.

APPLICATION FILED AUG.27, I920.

1,426,263, Patented'Aug. 15, 1922*.

.pP/im WITNESSES object is to provide a device by means of FRANK DOX, 0F PITTSBURGH, FENNSYLVANIA.

' snerannrr-rnrmrarne INSTRUMENT.

T 0 all whom it may concern Be it known that I, FRANK Dex, a citizen of the United States, residing at Pittsburgh,

in the county of Alleghenyand State of Pennsylvania, have inventednew and useful Improvements in Segment-Trimming Instruments, of which the following is a specification. V This inventlon relates to trnnmlng 1n struments, and more particularly to an in strument or device specially adapted for use in trimming the segments used in constructing cylindrical patterns. I 7

One of the main Objects of the invention is to provide a device of the character stated of simple construction and operation which may be produced'at small cost. A further which'the ends of segments' to be used in a cylindrical pattern. may be accurately trimmed on a radius corresponding to the radius of the pattern so as to insure accurate fit of these segments end to end. Further objects will appear from the detailed description.

In the drawings Figure 1 is a top plan view. of a device constructed in accordance with my invention.

Figure 2 is a front view.

Figure 3 is a section taken substantially on line 3-3 of Figure 1.

Figure 4 is a section taken substantially on line 4- 1 of Figure 1.

The device includes a flat base plate 1 of substantially rectangular outline one end 1 of which forms a straightedge for cutting or trimming the segments. As will be readily understood, in using the device the operator stands facing the edge designated A which, for the purpose of description, may be referred to as the forward edge, the edge B at the side of the base plate opposite to edge A. being considered as the back edge of the plate. A stop 2 is provided at the back of plate 1 and extends from straight edge 1. This plate is provided in its upper face with a dove-tail channel 3 which extends at an angle of degrees to straight edge 1. the forward edge of this channel extending from the point of intersection of the inner face of member 2 and straight edge 1 An adjusting or setting strip 4 is set into the upper face of plate 1* and extends from the forward edge of channel 3, this strip being graduated as shown.

specificatiouof Letters Patent. Pat gn td Avg, ra ification file August 27, 1920 I seriarn maaea A supplemental'channel 5 is provided at the other end of plate 1 and extends'fromthe main channel 8, this supplemental channel v being disposed in parallelism with straight edge 1 The channels 3 and 5 arefopen' at their outer ends and are adapted to slidably receive a setting block cor dovetail cross section. A setting screw 7 is through this block and provides simpleand threaded efficient means for securing the same in ad-' justment. a

I have found that by disposing the forward edge of channel 3 at'an angle of'GO' de-.

grees to straight edge 1? and settingthe forward end of block 6 at the mark on plate 1 corresponding to the radius of the pattern 1 in whicha segment is tobe usedfthe end of this pattern will be cut on this radius-by trimming it along the straight edge 1?. For

example, assuming that the radiusxof the l pattern is nine inches, block 6 is set with its forward end at the nine inch mark onthe scale. 'After this has been done, the seg ment is'laid upon the upper face of plate 1 so as to be in contact with the forward inner corner of member 2 and with the forward inner corner of block 6. The segment is now cut off along the straight edge 1 this has been done, the segment is turned over and placed in the same position. as before, the other end portion of the segment being cut off along the straightedge 1 By After i this means, both ends of the segment arecut i I on radii corresponding to theradiusjof the pattern to be, made thus insurm'gaccurate fit between the ends of the segments.

In cutting segments for patternshaving a radius greater than fifteen inches, :Iremove block 6 from slot 3 and place it in slot 5, using the graduated scale plate or strip 5 positioned adjacent to the inner edge of this slot or channel On this scale, the

graduations are not of uniform length since the scale is disposed parallel with straight' The instrument is, however, used edge 1 1n the same manner when us ng scale 5 as when using scale 4. The graduatlons on scale plate 5 of channel 5 are determined I I by experiment. For example, a segment of a given radius is placed upon the up er face of plate 1 in contact with stop 2' at t e outer end therewith, this segment being so arranged that a radius of the segment coincides with straight edge 1 The point at which the segment intersects slot 5- at the inner edge of scale plate 5*. is marked on this plate, this mark or graduation being marked by a number to indicate the radius of the segment. In example, it the segment has'a radius of twenty inches the number 20 would be inscribed adjacent to the mark at the point of intersection of the segment With plate 5 at the inner edge thereof. In this .Way the plate 5 can be accurately graduslot and a strip fitting into the same for holding the instrument or the device may be secured in any other suitable manner, as Will be understood.

What I claim is:

1. In an instrument of the character described, a base provided at one end With a straight edge, a setting member adjustable on said base along a line disposed at an angle of 60 to said straight edge, and a stop member secured to the base at right angles to the straight edge and intersecting the path of travel of said setting member.

2. in an instrument of the character de scribed, a base provided at one end With a straight edge and having a channel in its upper face, said channel being disposed at an angle of 60 to the straight edge, a block adjustable longitudinally of the channel, and a stop member secured to the base at right angles to the straight edge and intersecting said channel.

3. In an instrument of the character described, a base provided with a straight edge, a stop member disposed at right angles to the straight edge and intersecting the same, and a block adjustable along a line disposed at an angle of 60 to the straight edge and intersecting the point of intersection-of said stop member and the straight edge.

4. In an instrument of the character described, a base provided with a straight edge and with a dovetail groove disposed at an .angle of 60 to saidstra'ight edge, a stop member intersecting, the straight edge, a block slidable in said groove and having its lower portion corresponding in crosssection to the groove, and a set screw threaded through said block and bearing upon the base, i

In testimony whereof I affix my signature;

FRANK. DO'X. 

